Comparison of cervical os versus vaginal evidentiary findings during sexual assault exam

Evidence collection post sexual assault varies across the nation. The Ohio Department of Health has a standardized kit for evidence collection used during the forensic exams of sexual assault survivors. The protocol includes obtaining 4 swabs: 2 from the vaginal pooled fluid and 2 from the cervical area. The purpose is to determine if augmenting the state protocol with cervical os swabs and a comparison slide will improve evidentiary findings in adolescent and adult female rape survivors.

A descriptive study of 30 months for sexual assault female survivors over the age of 13 treated at a level II emergency department by a trained sexual assault nurse examiner (SANE). The comparisons of cervical os specimens versus vaginal pool findings were analyzed by the Canton-Stark County Crime Laboratory (C-SCCL).

Eighty-six cases were completed. After investigation, local law enforcement officials turned in 36 kits (42%) to be processed at the C-SCCL for the standard vaginal pool swabs and slide. The average estimated time interval between assault and treatment time was 20.46 hours (range, 2.83 to 80.83 hours). The average age of the survivor was 23.7 years, (range, 15 to 48). Eight percent (3/36) had only cervical os semen evidentiary findings. Forty-four percent (16/36) had positive semen evidentiary findings in vaginal pool and cervical os.

Successful convictions were aided by the cervical os research study, especially because vaginal pool evidence diminishes when collected after 24 hours, but may be present longer in the cervical os.